Over large parts of the world, humans have inadequate access to potable water. Significant research has therefore been directed toward developing products and processes for removing contaminants from water to render it potable.
For example, polymer beads have been applied in the treatment of water contaminated with dissolved organic carbon (DOC). In that case, DOC within contaminated water can adsorb onto the surface of the polymer beads. The polymer beads may also be provided with ion exchange capacity to provide for what is commonly referred to in the art as an ion exchange resin. Providing the polymer beads with ion exchange capacity can enhance their contaminant removal efficiency.
In use, polymer beads, with or without ion exchange capacity, can be packed into a column and the contaminated water passed through the column for purification. However, this “packed column” approach to removing contaminants from water can be limited in its efficiency.
An alternative approach to applying the polymer beads, with or without ion exchange capacity, involves stirring polymer beads with the contaminated water in a tank. This approach allows the polymer beads to have maximum contact with the contaminated water. However, subsequent separation of the polymer beads (which are typically quite small) from the water can prove difficult.
Polymer beads having solid particulate material distributed therethrough can enhance the ease of their separation from water either by increasing the density of the polymer bead or by providing another property such as magnetic susceptibility that can be used to separate the polymer beads from the water.
WO 96/07675 discloses polymer beads incorporating solid particulate material. The polymer beads may be provided with ion exchange capacity, and were found to be effective at removing contaminants, such as DOC, from water.
Despite the existence of effective polymer beads suitable for use in removing contaminants from water, there remains an opportunity to develop new polymer bead technology that improves upon, or at least provides a useful alternative to, known polymer bead technology.